The present invention relates generally to charging stations for energy storage systems, and more specifically, but not exclusively, to automatic cleaning of contact sockets of a coupler used with an electric vehicle charging station.
As electric vehicles (EVs) become more prevalent, there is a corresponding increase of installations for charging stations used with the EVs. These charging stations are installed at public and private locations, with either of the installations being classified as an indoor or an outdoor installation.
Each charging station includes an electrical coupler that includes two or more contacts that mate with the charging system of the EV. Dust and grime builds up on the contacts over time, particularly for electrical couplers used in public and/or outdoor installations. This contamination decreases the life of the electrical coupler and increases the electrical contact resistance between the coupler and the EV charging system. (Particulate contamination further provides a physical barrier on the contact surfaces that dramatically increases the contact resistance of a mated connection.)
Charging efficiency is very important in EV charging because of the large amounts of energy typically transferred during operation. Reducing charging inefficiencies is a system-wide goal for manufacturers, operators, and users. Outdoor charging stations are at great risk for developing unacceptable levels of contamination, particularly those in dusty areas. Public charging stations that are used many times per day are also at increased risk. Thus outdoor public charging stations that are used frequently have, in general, the greatest risk of wasting significant amounts of energy and user time.
To combat the contamination, these charging stations have a maintenance schedule in which a technician periodically cleans the contacts. The more at risk charging stations may have more frequent maintenance schedules, with any increase in maintenance schedule directly increasing operating costs for the charging station and decreasing availability for charging. Any on-site automatic maintenance performed between technician cleanings may extend the schedule and decrease costs and improve day-to-day charging efficiencies. Particularly as it can be the case that unplanned for increases of contamination between maintenance cleanings results in unacceptable charging efficiencies in the interim between the increase and the cleaning.
What is needed is an automatic cleaning contact apparatus and method that performs regular light cleaning of the contact surfaces.